CN110848332A - Intersecting-axis non-circular-face gear transmission mechanism - Google Patents

Abstract

A non-circular gear transmission mechanism with intersecting shafts, the transmission mechanism includes a small cylindrical gear and a non-circular gear, the rotation axis of the small cylindrical gear and the non-circular gear are not orthogonal, and during the meshing process, the small cylindrical gear The pitch cylinder of the non-circular gear is tangent to the pitch cone of the non-circular gear, and the tangent is the pitch cone generatrix of the non-circular gear; the pitch curve of the non-circular gear is a curve wound on its pitch cone, the non-circular gear is The projection of the pitch curve of the circular gear on the base of the pitch cone is a non-circular curve about the axis of the pitch cone. The transmission mechanism composed of a pair of gears meshing in the present invention realizes the reduction-variable speed composite transmission effect that can only be obtained with at least two pairs of gears when the previous intersecting shaft transmission structure is non-orthogonal, and simplifies the transmission structure to the greatest extent, shortens the transmission chain, and reduces the number of transmission parts. , Improve transmission efficiency and accuracy, especially suitable for occasions with any intersecting shaft structure, space constraints and reduced-speed composite transmission requirements.

Description

A non-circular gear transmission mechanism with intersecting shafts

technical field

The invention relates to the field of transmission machinery, in particular to a non-circular gear transmission mechanism of intersecting shafts.

Background technique

In the field of mechanical transmission, variable speed ratio transmission occupies a very large proportion. In order to achieve specific process requirements, many applications require the equipment to have a variable ratio transmission function. Among many gear ratio transmission mechanisms, the non-circular gear pair has the transmission characteristics of cams and gears, and can achieve high efficiency and high power accurate transmission ratio. It has been widely used in agricultural machinery, metallurgical machinery, printing machinery and light industrial machinery. a wide range of applications. Since the prime mover of the equipment is generally an electric motor with high rotational speed, it cannot be directly connected to the variable speed transmission mechanism to output variable speed motion. Therefore, in actual production, a deceleration mechanism is installed between the non-circular gear pair and the prime mover, so that the deceleration mechanism and the prime mover can be connected through the deceleration mechanism. The non-circular gear pair constitutes a series device to realize the deceleration and variable speed transmission. Compared with a single pair of gear pairs, this series of transmission structure increases the length of the transmission chain, increases the transmission space, and reduces the transmission efficiency. The deceleration and shifting functions are concentrated on a pair of gear pairs to realize the integrated transmission of deceleration and shifting. Any combination of reduction ratio and speed ratio can meet the requirements of the equipment for the reduction and speed change compound transmission effect, and can completely change the series structure of gear ratio transmission, simplify the transmission device, and improve the transmission performance of the mechanism, but the current non-circular gear pairs can only be used. The realization of deceleration and variable speed transmission in some specific environments cannot meet the needs of actual production.

Planar non-circular gears can realize variable angular speed transmission between two parallel rotating shafts. According to the shape of plane non-circular gears, they can be divided into many types, but in practice, elliptical gear pairs and eccentric circular gear pairs are the most widely used. In order to realize the integrated transmission of reduction and speed change through a pair of plane non-circular gear pairs, a small non-circular gear and a large non-circular gear need to be matched for transmission. According to the conjugate principle of non-circular gears, the rotation period T1 of the small non-circular gear and the rotation period T2 of the large non-circular gear must satisfy T1/n1=T2/n2, where n1 and n2 are the small non-circular gear and the large non-circular gear respectively. The number of cycles of the non-circular gear pitch curve, the deceleration effect of a pair of plane non-circular gear pairs is controlled by the parameters n1 and n2. When the difference between n2 and n1 is larger, the deceleration effect is more obvious, and n2 also controls the large non-circular gear pair. The number of cycles of the output angular velocity for one revolution of the gear. In order to realize the deceleration effect of the plane non-circular gear pair, the value of n2 must be greater than 1, which makes the large non-circular gear rotate once, and the number of cycles of angular velocity change is greater than 1, and this number of cycles is also limited by the reduction ratio, that is to say Once the reduction ratio of the plane non-circular gear is determined, the number of cycles of the output angular velocity is also determined, so it is impossible to achieve the reduction and variable speed transmission effect in which the reduction ratio and the number of cycles of the output angular velocity in the traditional series mechanism can be combined arbitrarily. To achieve some specific reduction gear transmission effects.

The space non-circular gear can be used to realize the variable angular speed transmission between two intersecting axes. The non-conical gear is a non-circular gear structure that appeared earlier in the space non-circular gear. Deformed elliptic curves and high-order elliptic curves, such as the oval bevel gear pair disclosed in Chinese Patent Publication No. CN1648490A, the eccentric elliptical bevel gear disclosed in Chinese Patent Publication No. CN102003538A, and the variable transmission disclosed in Chinese Patent Publication No. CN101975247A Ratio of high-order variable oval bevel gears. However, when these non-conical gears and flat non-circular gears use the same elliptical pitch curve or modified elliptical pitch curve, they achieve the same transmission ratio. Therefore, the speed reduction effect achieved by the non-conical gear is the same as that of the plane non-circular gear, and it is impossible to achieve any combination of the reduction ratio and the number of cycles of the output angular velocity. On this basis, the patent publication No. CN102518756A discloses a speed change ratio transmission mechanism composed of a plane oval gear and a special surface gear, which is used to transmit the variable transmission ratio between two orthogonal axes. The pitch curve period of the elliptical gear is 1. When the pitch curve period of the special face gear is an integer greater than 1, the speed reduction transmission can be realized, but like other types of non-circular gear pairs, this pair of non-circular gear pairs reduces The ratio is limited by the number of output angular velocity cycles, and it is impossible to achieve any reduction-speed composite transmission effect between the intersecting shaft structures. Another example, the patent publication number CN104500654A discloses a gear ratio transmission mechanism composed of a cylindrical gear and a face gear. It can transmit any speed reduction and variable speed transmission between the two orthogonal axes, but because the two rotating axes are orthogonal, the reduction-speed speed composite transmission cannot be carried out.

To sum up, all types of non-circular gears at present cannot realize any reduction-speed composite transmission between any spatially intersecting shaft structures.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a kind of non-circular gear transmission of intersecting shafts that can realize any reduction-variable speed composite transmission between intersecting shafts, can minimize the transmission space, reduce the transmission quality, and improve the transmission efficiency. mechanism.

The technical scheme adopted in the present invention is as follows:

The present invention proposes a non-circular gear transmission mechanism with intersecting shafts. The transmission mechanism includes a small cylindrical gear and a non-circular gear. The rotation axis of the small cylindrical gear and the non-circular gear is not orthogonal. , the pitch cylinder of the small cylindrical gear is tangent to the pitch cone of the non-circular gear, and the tangent is the pitch cone generatrix of the non-circular gear. The general transmission ratio function of the transmission mechanism during continuous transmission is:

In the formula, θ ₁ is the rotation angle of the cylindrical gear, i _j =Z ₂ /Z ₁ , where Z ₁ and Z ₂ are the number of teeth of the small cylindrical gear and the non-circular gear, respectively, and n is the order of the non-circular gear pitch curve , M is any positive integer, a _k and b _k are transmission ratio coefficients, and the transmission ratio coefficients are all less than or less than 1/i _j , and the pitch curve of the non-circular gear is a curve wound on its pitch conical surface , the projection of the pitch curve of the non-circular gear on the bottom surface of the pitch cone is a non-circular curve about the axis of the pitch cone, and its expression is

In the formula, r ₂ , θ ₂ are the radial and polar angle of the projection curve of the pitch curve of the non-circular gear on its pitch cone bottom surface, respectively, r ₁ is the radius of the pitch cylinder of the small cylindrical gear, and the non-circular gear pitch is the radius of the pitch cylinder. The equation of the closed pitch curve of the face gear is

In the formula, λ is the taper angle of the non-circular gear pitch cone.

Further, the value range of the sub-cone angle λ is 0-180°.

Further, the teeth of the non-circular gear are distributed along its pitch curve, and are enveloped by a standard spur gear slotting cutter, and the module of the standard spur gear slotting cutter is the same as that of the small spur gear. The number is the same but the number of teeth is more than the small cylindrical gear.

Further, the pitch curve of the non-circular gear is closed, and the simplest transmission ratio function of the transmission mechanism is

In the formula, n represents the order of the non-circular gear pitch curve, and ε is the eccentricity of the non-circular gear pitch curve.

Further, the small cylindrical gear is a spur involute cylindrical gear or a helical involute cylindrical gear or a cycloidal cylindrical gear.

Compared with the prior art, the present invention has the following beneficial effects:

Through a transmission mechanism composed of a pair of gears meshing, the reduction-speed composite transmission effect that can only be obtained when at least two pairs of gears are not orthogonal to the previous intersecting shaft transmission structure is realized, which simplifies the transmission structure to the greatest extent, shortens the transmission chain, and reduces transmission parts. , Improve transmission efficiency and accuracy, especially suitable for occasions with any intersecting shaft structure, space constraints and reduced-speed composite transmission requirements.

Description of drawings

1 is a schematic diagram of the assembly structure of an embodiment of a non-circular gear transmission mechanism with intersecting shafts proposed by the present invention;

Fig. 2 is the front view of the present invention;

Fig. 3 is the right side view of the present invention;

Fig. 4 is the relative position diagram of the conical surface of the non-circular gear pitch and the cylindrical surface of the pinion gear pitch;

Fig. 5 is the graph of the transmission ratio i ₁₂ of the small cylindrical gear and the non-circular gear;

_FIG . 6 is a graph of the gear ratio ib of the pinion gear and the non-circular gear.

Wherein, reference numerals: 1. Small cylindrical gear; 2. Non-circular gear; 3. Conical surface of non-circular gear pitch; 4. Non-circular gear pitch curve; 5. Cylindrical surface of small cylindrical gear pitch.

Detailed ways

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Referring to FIGS. 1 to 4 , the specific structure of an embodiment of a non-circular gear transmission mechanism with intersecting shafts proposed by the present invention is given. The transmission mechanism includes a driving gear and a driven gear that mesh with each other, the driving gear is a small cylindrical gear 1, the driven gear is a non-circular gear 2, and the small cylindrical gear 1 can be selected as a spur involute Cylindrical gear or helical involute cylindrical gear or cycloidal cylindrical gear, in this embodiment, the small cylindrical gear 1 is a straight involute cylindrical gear.

The axes of the pinion gear 1 and the non-circular gear 2 are non-orthogonal, the pitch surface of the non-circular gear 2 is a conical surface, and the pitch curve 4 of the non-circular gear is one of the conical surfaces 3 of the pitch. A non-circular curve in space, the teeth of which are distributed along its pitch curve and are enveloped by a standard spur gear slot whose modulus is the same as that of the involute spur gear The modulus of 1 is the same and the number of teeth is more than that of the small cylindrical gear 1; the cylindrical surface where the index circle on the small cylindrical gear 1 is located is its pitch cylindrical surface 5; as shown in Figure 3, the small cylindrical gear 1 and the non-circular gear 2 both rotate around a fixed axis, the angle between the rotation axes of the two gears is not equal to 90°, and the cylindrical surface 5 of the pinion gear segment is tangent to the conical surface 3 of the non-circular gear segment, and the tangent is the segment cone generatrix of the non-circular gear 2, The cylindrical surface 5 of the pinion gear pitch is in contact with the curve 4 of the non-circular gear pitch and keeps pure rolling; the small cylindrical gear 1 is connected with the prime mover, as the input member of the transmission mechanism, and the non-circular gear 2 is connected with the load, as The output member of the transmission mechanism, the general transmission ratio function of the transmission mechanism with the rotation angle of the pinion gear 1 as the independent variable is:

In the formula, θ ₁ is the rotation angle of the small cylindrical gear 1, n is the order of the non-circular gear pitch curve 4, M is a positive integer, a _k and b _k are the transmission ratio coefficients, and the value should be less than the reciprocal of i _j ; The transmission ratio of the non-circular gear 2 and the small cylindrical gear 1 is decomposed into the reciprocal of the product of the reduction ratio _ij and the speed ratio ib, that is, i ₂₁ =1/( _ij i _b (θ ₁ )), and _{i b is} The variable transmission ratio related to the rotation angle of the pinion gear 1, i _j =Z ₂ /Z ₁ , where Z ₁ and Z ₂ are the number of teeth of the pinion gear 1 and the non-circular gear 2 respectively.

The non-circular gear pitch curve 4 is a space curve wound on the pitch cone surface 3, its projection on the pitch cone bottom surface is a plane non-circular curve about the pitch cone axis, the expression of the plane non-circular curve for

In the formula, θ ₂ is the polar angle of the projection curve of the pitch curve 4 of the non-circular gear on the bottom surface of the pitch cone; the coordinate system is established with the conical vertex of the pitch 2 of the non-circular gear as the origin, and the closed pitch curve 4 of the non-circular gear is in this coordinate system as

In the formula, λ is the taper angle of the non-circular gear pitch cone, and the range of the taper angle λ is 0-180°.

When the non-circular gear pitch curve 4 is a closed curve, the simplest transmission ratio function of the transmission mechanism is

When the pinion gear 1 and the non-circular gear 2 rotate relative to each other, the cylindrical surface 5 of the pinion gear pitch is in contact with the non-circular gear pitch curve 4 and keeps pure rolling. At this time, the pinion gear 1 and the non-circular gear 2 can be The realized transmission ratio is expressed as i ₁₂ =r ₂ (θ ₂ )/r ₁ , the pitch curve 4 of the non-circular gear is a space non-circular curve, and the radial direction r ₂ of the projection curve of the pitch curve on the bottom surface of the pitch cone varies with The rotation angle θ ₂ of the non-circular gear changes, and the indexing circle radius r ₁ of the small cylindrical gear is a fixed value, so the transmission ratio i ₁₂ of the transmission mechanism changes with the rotation angle θ ₂ of the non-circular gear; when the non-circular gear 2 When the pitch curve 4 of the non-circular gear is closed, the pinion gear 1 and the non-circular gear 2 can realize the continuous reduction-speed composite transmission effect of the intersecting shaft structure, and when the pitch curve 4 of the non-circular gear is not closed, the small cylindrical gear 1 And the non-circular gear 2 can only achieve the local reduction-speed composite transmission effect of the intersecting shaft structure. In actual production, the former is more widely used. Therefore, the present invention uses the closed space non-circular curve as the pitch curve of the non-circular gear to further Explain the reduction-speed compound transmission scheme of the small cylindrical gear 1 and the non-circular gear 2 when the intersecting shaft structure is not orthogonal.

In the present invention, the shape of the pitch curve 4 of the non-circular gear determines the law of the reduction-speed transmission ratio of the gear pair. Therefore, the shape of the pitch curve 4 of the non-circular gear is a key factor in designing the transmission mechanism; obtaining the pitch curve 4 There are two methods, one is to obtain the pitch curve of the non-circular gear by formula i ₁₂ =r ₂ (θ ₂ )/r ₁ according to the transmission ratio required by the actual requirements, and the other is to directly use the existing gear ratio. Some spatial non-circular curves are used as pitch curves of non-circular gears. This embodiment uses the pitch curve of the non-circular gear obtained by the first method as an example to illustrate the reduction-variable speed compound transmission of the transmission mechanism.

The pinion gear 1 is connected with the prime mover as the input member of the transmission mechanism, the non-circular gear 2 is connected with the load as the output member of the transmission mechanism, and the first-order transmission ratio of the transmission mechanism is i ₂₁ =(1 +εcos(nθ ₁ /i _j ))/i _j , where i _j is the reduction ratio of the non-circular gear 2, ε is the eccentricity of the non-circular gear pitch curve 4, and n is the non-circular gear pitch curve The order of 4, θ ₁ is the rotation angle of the pinion gear 1.

Let an imaginary spur gear mesh with the non-circular gear 2 for transmission. The number of teeth and the module of the imaginary spur gear are known. When the imaginary spur gear rotates once, the angular velocity of the non-circular gear 2 is completed. A period of change, at this time, the reduction ratio i _j of the imaginary spur gear and the non-circular gear 2 is 1, that is, the transmission ratio of the imaginary spur gear and the non-circular gear 2 is the speed ratio i _b , then the The speed ratio and reduction ratio of the small cylindrical gear 1 and the non-circular gear 2 are respectively i _b =r ₂ /r _b and i _j =r _b /r ₁ =Z ₂ /Z ₁ , where r ₂ is given by The radius of the projection curve of the pitch curve 4 of the non-circular gear on the bottom surface of the pitch cone, r ₁ is the pitch cylinder radius of the pinion gear 1 , and r _b is the pitch cylinder radius of the imaginary cylindrical gear.

The following is a comparison of the four sets of data to illustrate the changing law of the transmission ratio when the axes of the pinion gear 1 and the non-circular gear 2 intersect.

(1) Take ε=0.15, n=1, m= _2mm , Z1 ₌ 17, Z2=70, λ=80°. Then when the non-circular gear 2 rotates once, the transmission ratio curve of the small cylindrical gear 1 and the non-circular gear 2 is shown in the single-period solid line in Figure 5, and this transmission ratio is divided into the reduction ratio i _j and the transmission ratio i _b . , the available gear ratio curve is shown as the solid line in Figure 6. The transmission ratio effect of the intersecting shaft non-circular gear pair is the same as the transmission effect of the bevel gear pair with the reduction ratio i _j =70/17 and the non-circular gear pair shown by the solid line in FIG. 6 in series.

(2) Keep the small cylindrical gear unchanged, take Z1=17, m=2mm, change the number of cycles of the non-circular gear pitch curve 4 n=2, other parameters remain unchanged, Z ₂ =70, ε=0.15, λ= 80°. When the non-circular gear rotates 2 once, the transmission ratio curve of the small cylindrical gear 1 and the non-circular gear 2 is shown as the solid line with a period of 2 in Figure 5, and the variation range of the transmission ratio i ₁₂ is the same as the first set of data , the cycle number of the transmission ratio becomes 2 with the cycle number of the non-circular gear pitch curve 4, while the reduction ratio i _j remains unchanged, which shows that the cycle number of the non-circular gear pitch curve 4 in the transmission mechanism can control the transmission. The number of cycles of the gear ratio i _b of the mechanism.

(3) Keep the small cylindrical gear 1 unchanged, take Z1=17, m=2mm, change the eccentricity ε=0.2 of the non-circular gear pitch curve 4, and other parameters remain unchanged, Z2=70, n= ₁ , λ =80°. Then when the non-circular gear 2 rotates once, the speed ratio curve of the pinion gear 1 and the non-circular gear 2 is shown as the dotted line in Figure 6. Compared with the first set of data, the reduction ratio i _j and the speed ratio cycle The range of the speed ratio _ib is increased, indicating that the eccentricity of the non-circular gear pitch curve 4 in the transmission mechanism controls the range of the speed ratio _ib of the transmission mechanism.

(4) Keep the pitch curve 4 of the non-circular gear unchanged, ε=0.15, n=1, Z ₂ =70, λ=80°, change the number of teeth Z ₁ =18 of the pinion gear 1, and its modulus remains unchanged , m=2mm. When the non-circular gear 2 rotates once, the transmission ratio between the small cylindrical gear 1 and the non-circular gear 2 is shown by the dotted line in Figure 5. Compared with the first set of data, the period of the transmission ratio curve remains unchanged, but the maximum value is the same as The minimum value changes. By calculating the change of the reduction ratio i _j of the two sets of data, it can be known that this change of the transmission ratio curve is caused by the change of the reduction ratio, indicating that in this transmission mechanism, the indexing of the small cylindrical gear 1 The radius of the circle determines the size of the reduction ratio _ij of the transmission mechanism.

When the pitch curve 4 of the non-circular gear selects other forms of curve, and the angle between the two gear shafts is other values, the transmission ratio law is the same as the above-mentioned non-circular gear transmission mechanism with a first-order transmission ratio function: that is, changing the non-circular gear The pitch curve 4 of the circular gear can control the speed reduction ratio _ib of the transmission mechanism, and changing the number of teeth of the small cylindrical gear 1 can control the reduction ratio _ij of the transmission mechanism. To sum up, the closed non-circular gear transmission mechanism composed of ordinary spur gears 1 and non-circular gears 2 can realize any reduction ratio between intersecting shafts, variable speed ratio period and variable speed ratio range according to practical applications. Combined reduction-speed compound transmission.

The above-mentioned embodiments are only to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. On the premise of not departing from the design spirit of the present invention, those of ordinary skill in the art can Such deformations and improvements shall fall within the protection scope determined by the claims of the present invention.

Claims (5)

1. The utility model provides an intersecting axis non-circular face gear drive which characterized in that: the transmission mechanism comprises a small cylindrical gear and a non-circular face gear, the rotation axes of the small cylindrical gear and the non-circular face gear are non-orthogonal, in the meshing process, a pitch cylinder of the small cylindrical gear and a pitch cone of the non-circular face gear are tangent, the tangent line is a pitch cone bus of the non-circular face gear, and the universal transmission ratio function of the continuous transmission mechanism is

In the formula, theta₁Is the angle of rotation of a cylindrical gear i_j＝Z₂/Z₁Wherein Z is₁，Z₂The number of teeth of the small cylindrical gear and the non-circular gear respectively, n is the order of the pitch curve of the non-circular gear, M is any positive integer, a_kAnd b_kAre transmission ratio coefficients, all of which are less than 1/i_j(ii) a The pitch curve of the non-circular face gear is a curve wound on the pitch cone surface of the non-circular face gear, the projection of the pitch curve of the non-circular face gear on the bottom surface of the pitch cone is a non-circular curve relative to the axis of the pitch cone, and the expression is that

In the formula, r₂，θ₂Respectively the radial direction and polar angle r of the projection curve of the pitch curve of the non-circular face gear on the bottom surface of the pitch cone of the non-circular face gear₁The equation of the closed pitch curve of the non-circular face gear is the radius of the pitch cylinder of the small cylindrical gear

Wherein λ is the coning angle of the non-circular face gear pitch cone.

2. An intersecting axis non-circular face gear transmission as claimed in claim 1 wherein: the value range of the taper angle lambda is 0-180 degrees.

3. An intersecting axis non-circular face gear transmission as claimed in claim 1 wherein: the gear teeth of the non-circular face gear are distributed along the pitch curve and are formed by enveloping a standard straight-tooth cylindrical gear slotting tool, the modulus of the standard straight-tooth cylindrical gear slotting tool is the same as that of the small cylindrical gear, and the number of teeth of the standard straight-tooth cylindrical gear slotting tool is more than that of the small cylindrical gear.

4. An intersecting axis non-circular face gear transmission as claimed in any one of claims 1 to 3 wherein: the pitch curve of the non-circular face gear is closed, and the simplest transmission ratio function of the transmission mechanism is

In the formula, n represents the order of the pitch curve of the non-circular face gear, and epsilon represents the eccentricity of the pitch curve of the non-circular face gear.

5. An intersecting axis non-circular face gear transmission as claimed in any one of claims 1 to 3 wherein: the small cylindrical gear is a straight tooth involute cylindrical gear or a helical tooth involute cylindrical gear or a cycloid cylindrical gear.

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